What is the relationship between the frequency (the oscillations of the wave in an up and down motion) and the wavelength (the horizontal difference between two crest ) of an electromagnetic wave?

If a molecule with a molecular formula of c13h18 is treated with an excess of h2 in the presence of finally divided pt metal under conditions required for maximum hydrogenation of the molecule to give a molecule with a formula c13h24, how many rings are in the molecule?

Light waves can move through , but they travel fastest when they move through a(n) .

A4.86 g piece of metal was placed in a graduated cylinder containing 15.5 ml of water. the water level rose to 17.3 ml. what is the density of the metal. i need the steps of how to solve it to so i can use a formula to work out other problems.